<?phpYii::import('zii.widgets.CPortlet');class ShowQA extends CPortlet {    protected function renderContent() {        $this->show_comments(0);    }    protected function show_comments($parentId) {        $criteria = new CDbCriteria();        $criteria->compare('parent_id', $parentId);        $criteria->compare('status', APPROVED);        $criteria->order = 'id desc';        $comments = Cache::model()->usingCache('Qa', $criteria);        $this->render('showQA', array(            'comments' => $comments        ));    }}